Commercial development of hydrocarbon fields requires significant amounts of capital. Before field development begins, operators desire to have as much data as possible in order to evaluate the reservoir for commercial viability. While data acquisition during drilling provides useful information, it is often also desirable to conduct further testing of the hydrocarbon reservoirs in order to obtain additional data. Therefore, after a borehole for a well has been drilled, the hydrocarbon zones are usually tested with tools that acquire fluid samples, e.g., liquids from the formation. These boreholes typically have well fluids at relatively high hydrostatic pressure. Because fluid sampling tools often also have one or more openings that allow fluid communication between the tool interior and the borehole environment (or ‘borehole exits’), it is desirable to control flow across these openings to prevent undesirable invasion of a sampling tool by well fluids.
In one aspect, the present disclosure addresses the need to enhance control of borehole exits.